When Corporal of Horse Frankie O’Leary rides through Windsor in full ceremonial kit on Saturday, he will not just be playing a key part in the royal wedding procession, he will be repaying a favour.

For the 31-year-old soldier credits Prince Harry with helping him on his own journey to the altar some years ago. "He rather kindly helped me get in with a young lady," explained O’Leary this week, referring to his days serving as radio operator, cook and tea-maker to the junior officer known in the Household Cavalry Regiment as Mr Wales.

The young O’Leary was walking back to barracks in Windsor with his then girlfriend, Nina, when a car slowed down and stopped.

The driver lowered the window. "See you later, Frankie," said Prince Harry affably. "See you later, Sir," replied O’Leary, as nonchalantly as he could.

Nina was bowled over. "I had to scrape her jaw off the floor," the soldier laughed, explaining that romance blossomed thereafter. Five years ago, they married.

It was just one of many stories circulating at London’s Hyde Park Barracks, where wedding preparations are now well under way.

In addition to the 800 guests at Prince Harry’s marriage to Meghan Markle on May 19, there will be a cast of thousands, including clergy, police and stewards. But for 62 of the 325 members of the Household Cavalry Mounted Regiment (HCMR), the ceremonial wing of the Household Cavalry, it is rather more personal. For they will be looking after one of their own.

The Ministry of Defence allowed the cameras to meet a cross-section of all the military personnel earmarked for the occasion, including street liners from the Royal Navy and the RAF.

The starring role, however, will go to the Household Cavalry, with whom Prince Harry served from 2006 to 2009 before transferring to the Army Air Corps.

They talked of their pride in their old comrade, not just for his service in the regiment but for his subsequent role in creating the Invictus Games for wounded troops.

Soldiers being soldiers, there was the odd joke about falling standards, too. "He’s got a very untidy beard," quipped O’Leary, who served with Harry in Afghanistan in 2007. All the men, however, voiced their admiration for the prince’s choice of bride. As O’Leary put it: "He’s pulled a cracker and he gets to take her home!"

The regiment will provide the Travelling Escort that accompanies the bride and groom on their journey after the service from St George’s Chapel, through the streets of Windsor, on to the Long Walk and up to the castle for the reception.

The regiment will also line the steps of St George’s Chapel and provide the State Trumpeters who will herald the arrival of both the queen and the bride.

"It's really important for us because he (the prince) served with us and he still wears our uniform on a regular basis," said Lieutenant-Colonel James Gaselee, commanding officer of the HCMR.

When the Prince of Wales married Lady Diana Spencer in 1981, his sister, Sarah-Jane Gaselee, was a bridesmaid at the invitation of the prince (who had been taught to ride racehorses by her father).

Gaselee’s abiding memory of that occasion is the huge box of chocolates he consumed while watching events on TV at a friend’s house. This time, his sister will be watching on TV while he takes centre stage.

As Prince Harry is not in direct line to the throne, it will be a smaller operation than the 2011 wedding of Prince William to Catherine Middleton. However, there's still a great deal to be done. From the tailor’s shop to the saddlery to the forge, things are gathering pace. Every horse on parade will receive a new set of steel shoes with tungsten tips.

Every trooper will spend up to three hours on the day before cleaning their "upstairs kit" (their uniform), another three hours cleaning their "downstairs kit" (the horse’s equipment).

It costs about £20000 (R332000) to dress the average trooper and his horse to the requisite standard, and up to £40000 for an officer.

Both the mounted troops and the stair-lining party will also spend hours polishing their boots. Lance Corporal of Horse Charlie Leslie, 29, explained that, in one sense, it is "just another day in the office". - Daily Mail